Hi all- A good sized rock smashed my rope this weekend. While checking it I found a section that did not pass the rope bending test. This is the test where you try and fold the rope in half in a particular place. Usually you can't because it forms a gentle curve, but I found a section that failed this test.

Does anyone know what causes ropes to fail this test? Is it a sheath problem or core problem? The rope looks just fine.

Considering that my parter was anchored 2 feet from where the block hit, I can't complain too much about a damanged rope.

Without actually seeing the rope I don't want to give you bad advice, but...

I did some experimenting with a retired, New England Equinox that was still in decent shape (passed the bend test). By removing a fiber strand or two from the sheath the rope completely fails that test. I think that test doesn't really offer anything to the integrity of the core. If you actually remove some of the core you will see its very soft and bendy fibers with no definite form. The sheath seems to be what is really what giving the rope its shape and resistence to bending.

Edit: All that being said, if you are at all in doubt, retire the rope. $200 is not worth your life.

If the damaged area is near the end of the rope, I would just chop that section off. Then you would have a perfectly workable, albeit shorter rope.

Unfortunately the damaged are is a good 5 m from the end of my 60 m. Which is okay I guess. I'll probably end up chopping it, but I want to see what everyone thinks first.

Your rope is 100% ok. So long as you use it for dog leashes, rugs and tie downs. A 55m rope still has plenty of use

I won't even post what happened to my cam which I'm still using.

Eric - it can be a possible indicator of a core shot. The only way to know for sure is to do strength testing. If equipment isn't in good physical working condition, just replace it.

The rope bend test is done in order to detect inner core damage, which is usually caused by crushing, not cutting.
It is performed by holding the section in question in a lazy loop of approximately 4" to 8" diameter (give or take depending on rope stiffness and diameter).
If the rope crimps in the area of question (visualize the Christian fish symbol) then it is time to retire the rope, or cut the rope at the damage point and use it for a short rope, sling or dog leash.